This invention relates generally to horological instruments, and more particularly to a detenting aggrangement for the stem of a wristwatch for a three position stem. As is well known in the art, the ordinary mechanical watch has a stem which may be rotated to wind the watch in the inner position, but which may be pulled out to engage a setting pinion so that the stem performs a different function in the outer position. The arrangements which detent the stem in the inner and outer axial positions usually employ spring fingers cooperating with frusto-conical surfaces on the stem and such surfaces have employed different slopes or included angles as shown in British Pat. No. 16,784 (A.D. 1915) to Depollier, and also as shown in U.S. Pat. No. 3,360,922 issued Jan. 2, 1968 to Rogers. Detenting arrangements have also been shown in the art for operatively positioning the watch stem in three different axial positions so that it can be rotated to perform three different functions, examples being shown in the aforementioned Rogers patent and also in U.S. Pat. No. 3,866,407 issued Feb. 18, 1975 to Wuthrich and assigned to the present assignee.
There are a number of applications where three position stem detents are needed in wristwatches, such as setting alarms, time zone hands, operating switches in different modes for solid state electronic watches, and so forth. When the watch operator manually pushes or pulls the watch crown, it is quite easy to locate the innermost and outermost positions. However the operator is never quite sure whether he has the stem in the intermediate position and this usually requires several tries.
Accordingly, one object of the present invention is to provide an improved detent arrangement for the stem of a wristwatch.
Another object of the invention is to provide an improved detent for facilitating manual location of the intermediate position of a three position detent in a watch stem.